As a fourth-generation light source, light-emitting diodes (LED) have shown their advantages in a plurality of applied fields such as landscaping, indication, display, backlighting, and special-purpose lighting, and have provided great effects with their high energy efficiency, long service life, and high speed of response. In the history of the lighting technology over the past century, LED has been developing for just several decades. And low-power LED has dominated its application. LED has been widely applied in the field of general lighting due to its features such as easy dynamic control of brightness and color, small dimensions, long service life, absence of infrared and ultraviolet rays in the light beams, and strong directivity of emitted light. However, in order to fully exert the performance competitiveness of LED in the general lighting market, we have to develop power-type light-emitting diodes, improve the light-emitting efficiency, and elevate the uniformity of color and luster.
Most of the power-type LEDs on the current market have a surface-clinging structure, which means that one or several LED chips are fixed to a plane substrate. Since the light-emitting angle of the individual chip will be not greater than 180°, this surface-clinging structure is affected by the angles of chips and the light-blocking effect of the plane substrate. Therefore the light-emitting angle of any LED having this structure will not be greater than 180°. Due to this angle limitation, several LEDs having this structure have to be assembled into a 3-dimensional module having a maximum light-emitting angle greater than 180° before they can be used for general lighting in replacement of incandescent light bulbs. Another 3-D luminescent 360° light source (Chinese Patent Application No.: 200780019635.4, Patent Name: A Semiconductor Light Source with a 3-D Support Used for Illumination of Physical Spaces) can also provide the 3-D luminescent effect. But a coaxial 3-D support is designed for this light source. It matching coaxial 3-D support is made by sheathing a cap having an extended guide pin (positive pole) with a hollow tube (negative pole). An insulating substance is used to separate and fix the negative and positive poles and several chips are fixed to the negative pole. The heat is dissipated only through the negative pole. And the threaded structure on the support cannot closely cling to the nut on the heat sink but only has a small actual contact area with the heat sink. Therefore the support itself has a poor heat dissipating effect which leads to poor lighting effects. In addition it involves a plurality of fittings and a complicated assembling process.